Combinatorial chemical synthesis requires simultaneously performing a plurality of chemical reactions. Often the problem of separating and characterizing the reaction products has to be solved. Reactor vessel arrays have been developed, wherein one specific reaction or sequence of reactions is performed on one or possibly a small number of adducts in each vessel, so that one or a small number of products are obtained, which may more easily be separated or examined. This type of synthesis is named “parallel synthetic chemistry” due to the relatively large number of reactions performed in parallel.
In order to obtain a high performance, synthesizers enabling performing chemical synthesis in solution, on solid phase supports or in so-called “tea-bags” etc. are required. A known type of synthesizer is characterized by the following features:
a dispensing system using one or more dispensing needles (these liquid handling systems were originally used for biological screening or diagnostic techniques);
a reactor block comprising a number of reactor vessels which allow performing a plurality of chemical reactions at varying temperatures, with shaking and under inert gas; and
a computer running a specialized software package which allows the programming and control of the individual synthesis steps.
Most known reactor blocks comprise a plurality of small reactor vessels which each have a top opening closed by a piercable closure, contain an inert gas atmosphere and are accessible through the closure using a needle. Liquids are added and removed through one and the same access. Less often reactor vessels are used which allow liquid transfer through the bottom of the reactor vessel using additional valves. Hence, the known reactor vessels are characterized either by a rather complicated access or a complex structure making them expensive.